


The Theory of the Möbius

by Veni_Vidi_Vixi



Category: Undertale (Video Game)
Genre: Frisk/Chara use both They/Them and She/Her, Multi, Time Loop, selective mutism
Language: English
Status: In-Progress
Published: 2016-02-07
Updated: 2016-05-23
Packaged: 2018-05-18 13:05:45
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 7
Words: 18,846
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5929486
Author URL: https://archiveofourown.org/users/Veni_Vidi_Vixi/pseuds/Veni_Vidi_Vixi
Summary: <blockquote class="userstuff">
              <p>“There is this theory of the Möbius.  A twist in the fabric of space where time becomes a loop from which there is no escape. So when we reach that point, whatever happened will happen again.”</p><p>When Sans, trapped in a time loop, finds a strange journal documenting other timelines, he sees a way out. If Sans cannot escape in this timeline he will, at least, record what happens and accumulate knowledge for future Sanses. Perhaps, with enough information, he will break this endless loop. </p><p>His only obstacle is a lone human. How difficult can this be?</p><p>So the impossible diary fills with each Sans's record and the skeleton continues hoping to piece together enough clues to escape. As the puzzle pieces fumble and fit together, Sans finds himself tangled up in a battle out of his control. There are only two ways out of this infinite coil and it all might depend on a tiny red SOUL.</p><p>Beta-ed by the fantastic <a href="http://eyesxsewnxopenx.tumblr.com">eyesxsewnxopenx</a></p>
            </blockquote>





	1. Attempt #27

**Author's Note:**

> Tags and Characters will be added as they appear. Frisk/Chara use both neutral and female pronouns. Monsters refer to them by neutral pronouns.
> 
> Beta-ed by the amazing [eyesxsewnxopenx](http://eyesxsewnxopenx.tumblr.com)
> 
> Seriously go check her out. She was an incredible help in making this even readable.
> 
> If the different fonts bother you, or if you cannot see the fonts and San's and Papyrus's lowercase/uppercase speech is annoying, then a version with unedited speech can be posted on request.

That last one was close. Closer that what Sans would prefer. Though in all honesty, there are a lot of things that Sans would prefer right now. He would prefer to be faster, he would prefer not to be in this accursed hallway, he would prefer for that damn brat to just go down and he would prefer his brother, all his friends, to be alive… But _wow_ , that last one was closer than some of the other attacks.

The knife’s edge glints a golden orange as it brushes by with such speed that Papyrus’s scarf shifts and flutters around his neck. He feels the drag of air and can’t help but mentally note the force going behind the blow.

_‘damn, kid. you’re really going for it this time.’_

He swallows and feels the ghostly motion of an imaginary Adam’s apple bobbing. He pulls the red cloth closer to his throat as if he could hide his nerves that the human would not see. The soft material rubs the bones on his fingers, stirring up the scent of tomato and snow. Sans remembers when it used to be course fabric Papyrus had picked up from who knows where - chosen for some costume party that had happened weeks ago. Over the last few weeks, it had been worn gentle with love and care and continuous use. Sans can still recall the excitement his brother had felt when he had finally presented his costume in all its grandeur - his 'Battle Body'. Papyrus spent the entire party claiming that a great Guardsman needed a great uniform. The grin he had when he bragged about it, promising that all the future guards will be wearing it soon, it was dazzling. Sans thought it was a silly and utterly ridiculous costume. But he also thought that it looked awesome on Papyrus. His Lil’ bro was always making him proud; so cool, so hard working and so kind. Perhaps too kind in hindsight…

Clutching the tattered scarf closer with one hand, he raises the other.

"ugh… you, uh, really like swinging that thing around, huh?… i could feel a lot of effort behind that one.”

Then he’s bringing his hand down, forcing, forcing them down. _'just go down. just stay down.’_ His wrist flicks as he bends gravity, hoping to slam them into the bones. _‘you must be almost out of HP by now.’_ Sans watches the human as they dart about, a strange look on their face. Their cheeks are flaring up in crimson patches, flat red eyes shifting as they watch his attacks and an indescribable grin painting their lips. They had avoided it again. The red soul heart taunts him, still remaining. The human is standing there, giving soft little pants from slight breathlessness. 

If Sans thought he was going to get a break, he was disappointed. Rather than catching their breath, the human just charges again, seemingly tireless. The knife sweeps forward with a swish.

He dives backwards and feels himself almost hit a pillar. There is brief panic when Sans thinks that he has fucked up and the blade’s point will finally hit. The knife is no closer than the last strike but no farther either. San’s eyes widen as he catches a glimpse of Papyrus’s reflection on the dagger, red scarf wrapped tight around his cheerful grinning face, as it whips past his face. His ears ring until he sees the blue power trailing from the reflection’s socket like wisps of fire. It was only San’s own face, making eye contact in that brief moment.

It still startles him. It throws him off. _Badly._ He has to take a moment to breathe, staring into the space where there had been a knife thrusting forward to kill him. The scarlet cloth around his neck is choking him. He huffs in little puffs of tasteless dust and feels warm light hit the back of his skull. He’s casted in shadow. Darkness swims before his eyes. The thumping in his chest calms down a bit as he recollects himself. He can see an image in his head – a small shoe pressing down on his brother’s skull, forcing it into the dirt, as his brother is turning to dust. He wasn’t even there to see it in person, but he remembers it as if he were. It’s torture. 

When he glances at the human, he sees that strange smile again. 

"s-so, listen… i know~”

"It’s strange seeing you wear it. You rarely ever do that.” 

The interruption jars Sans. The human rarely ever talks. They point at the scarf carelessly with the knife.

"You’ve only done it in two other timelines. I wonder why? Red suits you better than blue…” 

The skeleton’s eyes narrow, clinging tighter at the scarf. This was getting too close again. But in a different way, in a worse way.

"heh… so you’re admitting to screwing up the timelines, kid. i thought you would, uh, deny it or something.”

"Why?” The knife tip is pressing into a fingertip as they twirl it about. "I have already admitted this dozens of times. You never remember. Nothing changes.” Red eyes drill into Sans, making him almost take a step back before he forces his feet to be still. One slipper still squeaks on the marble floor. The human’s grin grows crueller. "You never change.” There is a small giggle; it sounds cute and young and Sans wonders just how old this human is. Maybe younger than he had first assumed. The giggle grows into a crazed fit. The laugh splits through the air, crashing into the golden atmosphere of the hallway. It reverberates around the columns, growing in size and pitch. The echo makes it sound as if there is a whole choir of demented mocking humans. It sounds monstrous.

It stops as sudden as it starts.

"Do you ever get bored of watching your brother die?” They catch their bottom lip with shiny white teeth, mouth stretching into a smile. Sans stills, feeling the air catch in his rib cage. _Too close._ "It would almost be boring for me if it wasn’t for that face. That face he makes when he realises that his idiotic trust has been betrayed. Geez, how fucking stupid can he get?! Dying over and over and never learning. It’s so funny!” The ground is shaking; he can feel the vibrations up his spine. In a moment of madness, Sans wonders if there is an earthquake. It takes a deep shuddering breath and roaring rage in his ear to realise that it’s him. He’s shaking, quivering at the emotions welling up in his soul. His eye burns. "The only thing better than the stupid look on your brother’s face is that dumb expression you make. You know _that_ one. When you realise that your brother is dead and you can’t even stop me.”

He makes eye contact with the human.

"Yes, that expression right there.” 

The skeleton slams his hand down, much faster than he thought he could. Summoned bones crash down like rain in a thunderstorm, stabbing into the ground. Each one slams down with the force of his rage, his sorrow, his hollowness. They stick and refuse to budge after the attack. They dot the hall like pins on a board. The air is so saturated with magic that they do not fade immediately. Sans is gasping at the end, jaw numb from clenching them too tightly and throat wet. Drops form on his head; he feels sticky and tries to forget that he is running out of time. His bony fingertips are tingling but he ignores that for the sight in front of him.

 _‘finally…’_ The human stands there, teeth gritted and wheezing. A hand rests on a bone as they clutch their side. They still had HP but the attack had hit. It had gone down, at least, a little. Expecting rage, Sans tenses when that hateful laugh builds up again.

"Haha, yes exactly! I will never get bored of it. I could RESET hundreds of timelines just to watch it over and over. It’s hilarious! That sweet moment when you finally understand that it’s your fault that he’s dead, that you killed him.” She thumbs the blade and crimson blood wells on the pad. It’s the same shade and colour of the scarf that is still choking him, strangling him with guilt. "You never change.”

Huffing, Sans forces out words that sound stilted to his ears. "well, you have already admitted to altering timelines, kiddo. it’s not like anything i can change that, right? or maybe i’m just too lazy to bother mixing it up.” He shrugs his hands, winking and smiling like this wasn’t cutting his soul.  "might as well stick with the classics. they seem to work fine since you’re still here.”

"Yes, and Papyrus is dead because of it.” 

"don’t say his name!” Sans grits. 

The flush of hot ire and cold horror surprises him. They fade quickly back to the familiar burden of remorse. Guilt clogs his mouth, settling heavily on his tongue. His brother’s face dances before his eyes and he can hear laughter, not their laughter but his. **‘Nyehehehe!’** He grips at the scarf, his shirt, his skull, pulling at it as if he could pull away the bad thoughts. There’s a skid of shoes squeaking on marble and the patter of running feet. A bitter taste builds in his mouth like he is sucking on a lemon. Papyrus is laughing at him, blaming him, accusing him and reminding him that Sans was useless, completely useless. Maybe he could have saved him, maybe if he had just been less lazy or… or…

 _Whoosh!_ He nearly misses the spark of the blade as it is thrusting at his head.

_‘right. still in battle. ain’t the time for daydreaming.’_

He dodges it on instinct. As it passes a drop of crimson human blood trails off the sharp edge, flies through the air and lands on his cheekbone. He can feel the tip of the knife catch on his brother’s scarf, tugging it away from his neck like this human ripped Papyrus away from him. Warm breath blows on his face and he is staring right into the human’s face, in close proximity. They are almost chest to chest and Sans feels panic. The last item of Papyrus is slipping away. Him and the human are sharing a breath, and San’s only comfort is that the knife has already missed him. That demented grin is splitting the kid’s face in two, and dead red eyes are boring into him. The dying orange light of the hallway is bleeding to red, filling the corridor with scarlet. Too much red. The heat from the fading twilight feels cold. Everything echoes. Time has surely stopped though birds still innocently chirp outside. 

The human’s eyes flutter shut, flush draining from their cheeks. The smile dips into a frown. Regret and sadness flicker through their expression. In the stillness of this frozen moment, they whisper.

"Sans… Please remember.” 

And then Sans is gasping, clutching at his chest. 

He pulls at his t-shirt, struggling through static noise and panic as he fights to remember where he is. Bony fingers get caught briefly in his heaving ribs, before pulling free. Reality is catching up to him and he runs his hand over his skull.

He’s… He’s… He’s at home, in bed. The ball of dirty sheets is at the head of the bed and he is slouching against it. He can hear Papyrus rattling about downstairs now. Pale late morning light is filtering into his room. He is home. He’s safe, and more importantly, Papyrus is safe.

" **BROTHER!** I WILL NOT ALLOW YOU TO WASTE THIS ENTIRE DAY IN BED! SENTRY DUTY IS A SERIOUS AND IMPORTANT JOB.” There was a pause before his disembodied brother’s voice added.  "THOUGH I AM PLANNING ON BEING A FAMOUS ROYAL GUARD SOON… WHICH MEANS YOU WILL HAVE TO BE _EXTRA_ RESPONSIBLE FOR SENTRY DUTY.” There are quiet thumps as Papyrus walks up the stairs. Sans is panting and staring at the door, shaking off the last vestiges of confusion. A bony hand drifts to his neck, then to his eye. Already the horrors of his dream were slipping from his memory. He tries clutching at them, getting flashes of terror, before releasing them abruptly. A seizing sense of sadness claws at his throat as he struggles from sleep, trying to frantically escape his dream and back to reality. He can hear Papyrus already on the landing when Sans realises that he needs to get dress. Now.

If Papyrus finds him in bed, he would not be happy. Again.

And though it was a pain and utterly tiring, Sans forces himself to bolt into action. Things still feel sluggish, though he knew he was moving quickly. He was getting used to this feeling when he got up in the mornings, sleeping in regularly. He just wasn’t a morning person. Yet, everything feels more… ‘off’ this morning. There was a new indolence that he couldn’t pin down or explain. He was just pulling his white turtleneck over his head when Papyrus crashes into his room. The door flies open, thumping against the wall and almost knocking the perpetual whirlwind of trash off of its axis. The bang made Sans flinch, stunning himself. The skeleton rarely startled at loud noises. He throws a sleepy grin over to his little brother. 

"yo, bro. just a bit behind this morning.”

"REALLY SANS? AREN'T YOU A BIT BEHIND EVERY MORNING?” Papyrus’s eyes narrow in thought. "MAYBE WE SHOULD MOVE OUR SHIFT TO LATER,” and his tone brightens up as the idea fully forms, "THEN YOU WILL NEVER BE LATE, SANS! NYEHEHEHE.” Papyrus laughs and Sans can’t help but join in. Papyrus was a real ray of sun in this place, something good. It was hard not to laugh with him, no matter how exhausted Sans was feeling when he woke up. His awesome baby brother shouldn’t have to worry about his older brother. Especially when Pap was already feeling down himself about the Royal Guard thing. Sans would get over whatever odd melancholy he seems to be suffering from today. 

"COME ON YOU… _'LAZY BONES.'_ I MADE SPAGHETTI FOR BREAKFAST!”

"of course, you have bro. you know it’s my favourite meal. it’s _'pasta'_ -bly better than Grillby’s fries.” Sans winks and grins, picking up his blue hoodie from the floor as he exits the room pass Papyrus. He stifles a laugh at his brother’s muffled groan, before adding in a cheeky tone. "just don’t tell Grillby i said that, Pap. i’m _'Alfredo'_ what he’ll do to me.” He was quaking with barely hidden mirth as he heard Pap mutter _'Oh God.’_ behind him. Shaking off the peculiar feeling from his nightmare that was crawling up his spine, Sans decided that he would make today a good one.

Later that day, a human appears and kills Papyrus.


	2. Anger is better

San supposes that maybe he shouldn’t be so shocked, but he is. Clutching at his brother’s scarf, he stares blankly ahead at the snow banks. That dream… He’s normally so perceptive but he ignored things, pushed suspicious things from his mind, forgot about the time anomaly and blamed it on his indolence. If he had just paid attention or or followed his instinct, then maybe… 

There is a hollow in his chest as he mourns his brother. The world blurs around him as water slowly drips from empty eye sockets. He quietly cries cold water, feeling it slowly run down his skull and fall into the snow. Though he has no distinct memories, Deja vu taunts him. This had happened before. Or at least, he thinks it has. Slow-moving tears freeze to the cheekbones, dimly sparkling. His fingers brush his cheeks, wiping away flakes of frozen tears. They glitter on the tips of his fingers like tinsel on a pine tree. His bones creak, breaking the quiet that blanketed the snowy region.

He has to stand up. Monsters were evacuating, fleeing from the terrible creature, a human with a smile. Snowdin was already tumbling into muteness, only broken by San’s gentle breathing as he numbly pushes the door open to their, his, home. 

Sans looks around briefly disorientated, wiping the last of the crystalline tears with his hoodie’s sleeve. He doesn’t remember forcing his heavy bone legs to bear his weight, or walking the short distance home, or even taking one of his legendary shortcuts. He was just… suddenly here. The living room is unlit except the light that streams in from the uncovered windows and the open door he currently stands in. He can feel his bony hands scrape and protest at their tight grip around the doorknob. He releases it stiffly and glances at his other hand. Pap’s scarf hangs there, fluttering from the wind outside, and being dragged and pushed farther into the house. White trails from it, a swirl of agile grey specks that catch the light before vanishing into shadows, and the skeleton drops it. What had seemed like snowflakes under the pale outdoor light was actually dust. 

His brother’s remains. 

His hands shoot to his mouth, trying to quash the intense nausea that threatens at the back of his skull. He can taste ketchup and salt on his tongue from Grillby’s earlier, mixed with a strange acidic flavour that he is not familiar with. The faint scent of fresh snow is replaced by something musty and then dry thick dust is clogging his nasal bone. His hand had been touching his brother’s dusty remains and now he has just put it on his face. 

Horrified, Sans throws his hands away and wipes them against each other. The motion makes clacking noises and sends small puffs into oblivion as he tries to get it away! He’s backing out of the house, his heelless slippers picking up snow as he shuffles backwards, escaping. Once Sans outside again, buffered by the cold wind and clumpy snowflakes, his skull clears. The skeleton looks up at the house, and the place already looks haunted to him. How many times has he done this?

"wow… what am i even doing?...” 

In his head, Sans chastises himself for calling Pap’s dust ‘it’. What would his brother say? The big softie is always so considerate, sometimes a little childish but that’s just because Sans spoils him, and he would never call someone else’s dust an ‘it’. Sans smiles despite the hole punched through his rib cage. It’s so surreal, Sans keeps thinking that his brother is going to pop out of the door. It feels like he is still here, just out of sight - like a phantom limb. Only the void in his soul reminds him of the truth. Maybe, just for a moment, he could pretend that this was all just a bad dream…

In the best impression he could muster of his brother’s voice, he speaks. It starts off soft before booming into the taller skeleton’s boisterous way of speech. "sans… BROTHER!! No self-respecting GREAT GUARDSMAN would dare disrespect a monster’s remains like that! I, the AMAZING PAPYRUS, will not stand for it!" Sans straightens his back slightly, ignoring the small imperfections of the imitation. "You shall have to apologise! As punishment, you will have to do the Junior Jumble. By YOURSELF! Nyehehehehehe..."

A strained quiet settles as the falsified laughter echoes and dies out.

"okay, Pap. ya got it.” Sans sighs, letting his normal voice break the silence left behind. The impression is a poor substitute for the real thing. The Papyrus-shaped hole in his chest grows. 

This might be a puzzle he can’t solve by himself. Reluctant to re-enter the house, the short skeleton trudges around to the back of the house to his secret lab. The sound of the key clicking in the lock gives a sense of familiarity in this strange new Papyrus-less world. 

Once inside, he empties out his slush-filled slippers and pulls off his wet socks. He uses the tip of his finger to wiggle out the ice trapped between the metatarsal bones in his foot. After he throws down his jacket onto the floor and collapses on top of it, Sans contemplates taking a nap. All this emptiness was exhausting; who knew anguish would make you sleepy? He is _bone_ -tired and would like nothing more than to just go to sleep and never wake up again. Well, not quite. There was one thing he’d rather do – confront the human that was the source of his and everyone else’s suffering. 

That would be suicidal. Out of the two brothers, Papyrus was the stronger one. Sans had better skills, different skills, and knew more about magic. But his brother, despite his compassion and gentleness, was the fighter in the family, or at least “trained” to be it. Sans has always preferred his books, his telescope and his lab. Or he did until a couple of years ago. He mostly lazed about and slept nowadays, or hanged out with his brother pretending to be on Sentry duty. He also had those odd jobs Pap had convinced him to get. 

Sans knew more but he was weaker. In short, he needed the power Papyrus has, had, to actually perform any techniques formidable enough to use against the human. Either that or he needed to outsmart the human. But it might be a Sisyphean quest. He didn’t know for sure, but Sans was theorising that the human could somehow travel through time or, at least, manipulate it. For the last 3 years, there had been occasional reports - little hiccups in time. Suddenly, since yesterday morning, there had been an almost constant stream of reports. Timelines were jumping about, rearranging and looping. Everything was moving back and forth. The time anomaly had increased exponentially and Sans had no idea why. Then the human strolled out of the ruins with dusty shoes, behaving oddly and reacting to things that hadn’t yet happened. How do you outsmart someone who could know the future? He rests his chin on his hand, elbow on his knee, knees drawn up close to his chest, pondering. 

He sits for a while with eyes unfocused on the space in front of him; a thousand yard stare in a 10 yard wide room. Sans isn’t sure what catches his eye or why he snaps out of his zoned out state but he suddenly finds himself focused on the side of the room across from him. He feels compelled to at least look.

Blue-prints tacked to the chrome walls and sketches left in semi-disorder on top of a narrow metal workbench sit opposite Sans. Forcing himself to roll to his feet, he approaches them. Many of the papers in his lab were messily written in this strange code. Sans roughly knew how to translate the odd symbols, though he could never remember or figure out why he had encoded them in the first place. The skeleton wasn’t a fan of cryptograms. He trails the tips of his bone fingers over a small pile of sketched machine parts, watching a semi-written story appear as the papers are smeared across the bench. His mind struggles to decipher the code initially, either because it had been a while since he has looked at the papers or because grief had addled his mind. They were prototypes for the parts of a machine that was now snuggly in the care of Dr Alphys. The memories of how he was involved with the creation of it were somewhat distant and blurred, despite it only being built less than 5 years ago. He hasn’t asked about it in a long time and Alphys has not told him anything. 

Sans used to wonder why his memories of his earlier inventions were so fuzzy. He knew them very intimately so there was no doubt that he had made them, but he was never sure how he came up with the concepts or turned them into reality. 

He runs his hand down to the far right of the workbench and opens the drawer there. Inside sits folders and piles of more cipher blueprints; finalised and probably already built or being built. He lifts the top-most paper; it is covered in notes written in his regular handwriting about the time bumps that started 3 years ago. They were smaller than the pandemonium that began yesterday, but still incredibly fascinating. They are just incomparable to the figurative earthquake that was currently twisting around the timespace continuum. The skeleton had thought that he had finally found the source of this new massive anomaly when he first saw the human. He had never met a human before but his instinct and sharp observation was trying to tell him that was wrong. His memory tugs him back to when he first met the human - who had turned around before he even revealed himself, who almost appeared to recognise him, who had behaved strangely like they had seen everything before. There was fear in their eyes: fear, relief and something darker. Something angry.

He had thought that maybe if he made them happy, the anomaly would stop. They would let time continue on naturally as the universe intended. The human could have changed and everyone deserves a chance. Secretly, he felt like they could have once maybe been friends…. 

He had been too kind, just like Papyrus, Sans had been too nice. 

It seems pointless now. He is empty, his heart was punched out of his ribcage. _'did it matter?’_ He drops his theories and thoughts on potential time-travelers and closes the drawer again. 

He comes to the middle right drawer next, pulling it out and expecting to find more drafts. Only there is something new here. Bounded in worn black leather, a slim notebook sealed with dark grey twine sat among the papers.

Sans has no memory of this book.

Sans glances around as if suddenly expecting the perpetrator who had left this foreign object to announce themselves and appear. When no one is polite enough to step forward and claim the prize, Sans shrugs, unties the string and flips open to the first page instead. Code stares at him in scribbly pictures; the same writing that covers most of the blueprints, that Sans could never duplicate though he must have written it. His eyes widen, because beneath it was a short note in his own penmanship. 

_'sans,_

_a gift that may aid you against the human. _

_time loops will work against you; timelines can be made and destroyed. they can RESET. write down what you must remember before you forget everything._

_don’t worry - i will always make sure you get it back._

_remember, i am your Friend. they are the Enemy._

_stay **DETERMINED.** _

_your fellow scientist,_

_Dr W.D Gaster’_

“Dr. Gaster ?”

Sans blinks. He has never heard of a Dr Gaster before. He sweeps his hand over the deep blue ink that probably came from his favourite novelty pen. The paper is a pale dry brown, wrinkled in the corners and dogged ear. It smells of ozone. The paragraph symbols at the top were smudged, smeared and seemed water-damaged, making the thick black ink bloom in several colours, obscuring the code. After studying it for a few moments, he realises that his own writing is merely a translation of the above cryptogram. 

He scours his entire memory. He has never seen this book before and he has certainly never written in it. He bends the spine, splaying out the pages to flick through them, briefly scanning for any more of his handwriting. The first dozen pages of the book were in the messy cryptic code followed by a quarter of the book in his recognisable juvenile font. San’s handwriting is unique - small curved playful letters, evenly spaced and precisely written in blue ink. A juxtaposition of his lifestyle, it was so neat it could almost be a computer’s typeface. Most just called it strangely childish and obnoxious. Sans likes his own handwriting. He also knows he is the only monster in the entirety of the Underground that could use it. 

He holds the book by the back page, the spine flexing and flashing off the inner pages, with his other hand gripping his skull. _'oh boy…’_

This could be proof that time travel was possible. Sans reels as he realizes his theories could be right; other timelines exist and a human is wreaking havoc on them, twisting temporal space together into loops and knots. Only Sans could have written this. Did a future Sans, or a Sans from a different time line, write this? Was this due to the abnormality or something else?

_'wow, how is this even possible? forcing us to do this same stand-up routine over and over? the human really is a freak.’_

The empty chasm in his chest hurts again. He still feels so vacant, despite all this.

He needs Papyrus. Sans needs his little brother, his uncomplicated innocent little brother who always came up with the simplest solutions. Papyrus always kept Sans together, when he could no longer manage on his own. Sans slams the book down on the workbench and grips the edge tightly with both of his hands. He is huffing as he stares down at his own reflection, the shiny surface slightly warping his image. He looks as haunted and as empty as his house.

The skeleton pushes off the bench, whipping up the book and stomping back to his discarded jacket, which he promptly collapses onto again. He yanks it open to the first page. His eyes follow each line of each passage carefully. 

As Sans flicks through the journal he finds that the coded writing is similarly damaged throughout, and beside each entry is his own translation. His own partial translation at least - his code was used disjointedly in messy scrawling scribbles that were hard to distinguish, never mind decipher. Whoever this Gaster guy was, he seemed to be having one hell of an experience. Or had. There were lots of mentions of void and darkness and questions posed as if from a scientist – it sounds impossible and whoever Gaster was, he was probably dead. (Or was going to die? Time travel was complicated that way.) How, then, did he write a note to Sans and leave behind his notebook in this secretive place?

Honestly, if there wasn’t a murderous rampaging human destroying everyone and everything Sans loved… Then he might look into this further. Rereading the first note addressed to the skeleton, he decided that a reasonable conclusion was that this Dr Gaster was probably also a time traveller, and had given Sans this book in hopes of him getting rid of the human. 

He flips to the section where Gaster’s squiggles end and his entries begin.

And it starts with a terrible, terrible sentence. 

_**'Pap is dead.’** _

The words blur before his eyes and he feels the paper crunch beneath his fingers. The sound of crinkling parchment fills the air. The empty void in his chest starts to fill with hot fury.

He sucks in air, the cold doing little against the heat of his rage. It is harder to know about his brother dying before than it is just theorising about it. How many times has Papyrus died? How many times has Sans himself died?! Loathing for this tiny human that dares rip apart time, only to kill again and again, fills his bones and replaces the marrow with an overwhelming wrath. It was going to pay for this. 

The hollow in his chest left behind by his brother is full of ire. It blinds Sans.

Beneath that was something about the human continuing, killing and sparing as it pleased! Sans barely pays mind to the actual tale, still digesting the lil tidbit about his brother being killed in other timelines. It mentions a battle with Asgore, souls disappearing, monsters trapped, blah, blah bah and the human leaves and is gone forever. 

Except it obviously came back!

It still isn’t satisfied. 

Sans hisses under his breath. This bitter fury was good; he was tired of being vacant, caught on the edge of an empty emotionless existence. Anger was better than tears, better than grief, better than guilt. Sadness would not bring his brother back but anger will get rid of the thing that stole him. He quickly flicks through the numbered entries; not reading them, just counting them. 28 in total, 28 timelines destroyed to fed that beast’s blood lust. Papyrus doesn’t die in all of them, it was apparently fickle about who it killed when. Usually someone dies - an innocent monster, Undyne, someone called Toriel, a spider monster… Sometimes the human killed many; sometimes it killed only one before the entry is cut off. But then there are those 10 wretched entries where it killed everyone. 

The name Frisk and Chara is thrown around, sometimes switching during an entry, but he didn’t care. Once he finds out how to stop and kill this thing, everything will be better and the timelines will stop disappearing. He can read the rest later. He opens entry #27 – the last Genocide timeline. It’s one of the shorter entries. At the bottom of the page is a tally score, depicting how many times that Sans fought and defeated the human. 37 tiny scratches were pressed onto the page. The entire page was written bleakly; it was brief and lack San’s usual humour when writing his reports.

_'#27_

_Pap is dead. again._

_everyone is dead. again. the human has been busy._

_i managed to save Pap’s scarf – ~~heh, i can’t believe how itchy it is.~~ the human is heading towards the barrier. i think this is all my fault. which is hilarious. except, not really._

_i collected some DETERMINATION from Alphys’s lab. the final battle will take place in the golden hallway near the palace. i will judge this human guilty of its sins and i will deliver its punishment._

_for Pap…_

~~_i sometimes still hear his voice, i think i_~~  
~~_i am sorry, i should have_~~  
_~~i’m scared that~~_  
_**i’m in the hallway now.**_

 _t=0: 150 cc* of liquid DETERMINATION injected into SOUL._  
_t=2 minutes: previously noted symptoms occurred. multiple gasterblasters can now be used, there’s a sharp increase in power, a surge of energy in the left eye and melting has not begun yet._  
_t=5 minutes: human arrives._  


_*nb: following the advice of a previous entry, no more than 160cc was injected. melting was minimal and mostly unnoticeable._  


_i will defeat the human before it RESETS the entire timeline. i dunno what will happen to me afterwards but whatever it is, i probably deserve it. ~~maybe, i’ll go to Grillby’s.’~~_


	3. What Monsters Fear

**Notes for the Chapter:**

> I'm gonna try and up-date every Sunday. I got a hectic life so I won't always be able to, but I think I'll try anyway.

The injection of DETERMINATION is a novel idea to Sans. 

The notion had not occurred to him previously - it seems obvious now. The human is using its own DETERMINATION to change the timelines, forcing everything into a loop. A monster’s soul does not contain as much DETERMINATION as a human’s soul, which places monsters at a disadvantage. But if Sans injects himself with some DETERMINATION he could, in theory, hold his own in battle. Maybe even win. Maybe stop it from erasing the timeline. 

A ‘maybe’ was more than Sans had originally hoped for. Part of the theory obviously works judging by the 37 penned victories. The only failure was that this previous Sans could not stop the RESET and kill the human… Or that he was killed. 

Risk of death or not, his SOUL won’t settle until he destroys the time anomaly. Anger is making him his bones tremble, clacking together with excitement and a ferocious bloodlust that Sans did not know he was capable of. He wonders at the guilt that his predecessor seemed to feel; this is clearly the human’s fault, that dirty brother killer!

He has the knowledge; he could kill it. He _wants_ to kill it. 

_'sorry lady, this is why i don’t like making promises.’_

The skeleton pushes himself to his feet, yanking up his hoodie from the floor and pulling it on in exaggerated movements. He jerkily pulls the hood up and over his skull. Anger was making him twitchy and restless. Then he is shoving the journal into his pocket. The brown twine used to tie it shut hangs from his pocket like a long mouse’s tail, stretching to the floor and trailing behind him. He pulls on his socks and slippers, tapping his toes twice against the tiled floor. The skeleton spares one last glance around the lab.

Then he leaves through the door, to a ‘shortcut’ that leads straight into Alphys’s Lab.

While Snowdin is soundless and abandoned, quiet firmly settling over the snowy banks in a thick choking blanket, Alphys’s lab is a cacophony of chaos. Sans turns and sees a giant screen of the human moving forward through the Hotlands. It is approaching the MTT Resort. Alphys herself is standing on her desk, hands twitching and grasping at each other. Her voice trembles as she tries to direct more and more monsters into the main Lab. A cloud of confusion and fear clogs the air. The scientist continues on, though, forcing her anxiety aside. 

Sans takes a deep breath, unclenches his fists and forces a smile, before pushing towards her through the crowd.

Alphys is stammering through a set of instructions - her voice is loud but shaky. It is not until he is at the foot of the table that Sans catches her attention. Alphys jumps and physically flinches backwards, knocking a stack of empty insta-noodle pots off the edge of the table. The clatter they make when they hit the ground is swallowed up by the noise of the crowd of monsters. The smell of stale processed pork wafts through the air. 

“Eek!”

Alphys stares at the skeleton as if he were an illusion; the scientist’s eyes are red-rimmed from earlier crying. She clumsily crawls off the table, knocking more papers and food packets down. “Ah, Sans! I-I’m so glad to see you.” Relief and joy swell in her chest. Alphys almost goes to hug him, but something in the skeleton’s expression stops her. Darkness lurks under the grin. “After the, uh, human had gone through Snowdin and, um… I thought…” She trails off, wringing her lab coat and staring at her scaly feet poking out from underneath. “Listen, Sans, I’m sorry about Papyr~”

"actually, Alphys, i came here to pick some stuff up. ya know, my home lab just isn’t as well stocked as here.” There is a tension in his voice as the skeleton forces cheerful nonchalance into his tone. It sets Alphys on the defensive though she tries to mask her apprehension. Sans’s lab is a secret known only by Sans and his once-upon-a-time close colleague, Alphys. 

“Of c-course Sans! What do you need?” Her voice is less timid and a little friendlier, though the underlying sadness remains. “Whatever it is, I’m sure we can find it in the Lab! And I could really use your help in the evacuation.”

The skeleton glances to the side, guiltily scratching the back of his skull with a half-cocked grin.

“You… You are staying, right Sans?” Alphys whispers and Sans almost misses it over the background clatter. When he doesn’t answer immediately, refusing to meet her eye, Alphys pales. She can feel the blood drain from her face leaving behind cold realisation and a sharp fear for her friend’s life. “P-p-please Sans… Tell me you are staying.” 

"Al.” And the nickname and cheerful tone make the lizard’s scales crawl. The actions and tones were all wrong. Sans is acting all wrong. "i’m kinda just here for DETERMINATION. i know ya have some.”

**“No!”**

Several monsters turn towards the source of the horrified gasp. 

“How? H-how d-d-do you even know that-t?” Alphys’s shaking is worse now, jostling her glasses, on a verge of a panic attack. “I’ve only started directing monsters into t-there. I just told them about the… I didn’t want a-anyone to k-know.” Her tail swishes to and fro, batting against the edge of her too long lab coat. Guilt flashes across her face - guilt and terror. “Sans, whatever you are planning, you c-c-can’t.” 

"i just need DETERMINATION, doc.”

“But _why?!_ ” Alphys screeches out, loud and high pitched. Fat tears sit at the corner of her eyes, her nose is starting to run and her trembling is almost knocking her round glasses from her nose. She keeps absently pushing them back up her snout. A child’s voice distantly asks a muffled question, barely heard over the murmur of the rippling crowd. Alphys turns to the mass of evacuating monsters as if just remembering that there is, in fact, an audience to this teary display. She throws her hands up to her face, hiding behind scaly yellow palms. The sleeves of her too big lab coat sway; they smell of acetone and mechanical oil. The familiar scents fill her nose each time she sniffs, calming her. Chubby shoulders straighten, as if the scientist is trying to brace herself mentally for this conversation. “Sans. Why do y-you need D-DETERMINATION?” Her hands nearly stifle the question. 

Sans shrugs easily. "welp, i guess i better tell ya. you look darn serious, Al.” He thrusts his hands into his pockets, feeling his bones quiver under the fabric. The rage simmers on but he tries to hide it. _'best not worry Al, ya know.’_ He grins widely, carefully keeping his voice steady.  "i've got a plan to save the Underground. it’s time to stop lazing about and _‘sans’_ up for what’s right.” He winks at Alphys as he makes the small joke, ignoring the horror and worry peeking out from between her fingers. 

The ill-placed humour drives Alphys to a snapping point. Sans is just trying to play this off lightly, just like any comedian would in a bad situation, but she can’t understand this… this inappropriateness! She throws her arms away from herself and stares Sans directly in the eye sockets. The shy scientist rarely made eye contact, but through a pair of thick lens, she watches Sans, trying to plead with him. Her face is dripping with misery and confusion; her eyes look panicky. The skeleton forces himself not to look away, not to hide from this flagrantly open display he doesn’t know how to deal with. Alphys is never this brazen, but times change. 

She’s frantic. She can’t lose another friend today. Not after Undy~…. 

She sucks in a gasping breath, before pushing it out through her teeth. Her voice shakes slightly but she doesn’t stutter. Alphys speaks loudly with an almost violent desperation. “Undyne… Undyne went to go meet the human too.” The heavy implication is there. Alphys sees San’s easy expression twitch briefly - a grim moment of realisation, anger and pity – before he’s trying to smile again, avoiding eye contact. He refuses to return the emotional gaze. 

The skeleton is livid. His finger bones grind together in his pocket as he squeezes them into a fist. Undyne is dead too, and it only fuels the fury. Hiding this ever-growing resentment is hard. The book is heavy in his hoodie; like an anchor but it drags him down rather than offering security. He is strained, trying to keep a smile. He mustn’t let Alphys know how furious, how downright _murderous_ he really is.

He doesn’t want his friend to see him like this…

But it’s hard, it is really hard.

Sans says nothing. 

“Undyne is dead! Sans, I know what you are going through. Papyrus is de~”

" **don’t!** don’t say it!” Sans growls out, teeth gritted and fists curled up tight. The words break something inside of him. A magical girl mug flies across the room in a blue blur, shattering against the metal wall. The cold, hot chocolate and fragments scatter in a wide spray. A nearby monster yelps and a baby starts crying somewhere. The other monsters in the room quieted into murmurs, rustling like a flock of ravens. Some still move into the lab - the ones who have young children and the like – and the voice of the crying baby fades.

The skeleton turns to them, daringly. The frightened crowd stares at him, tension rippling through the mass, as they waited with baited breaths. He looks back to Alphys who has her claws to her mouth again, water streaming down her cheeks. It gleams under the harsh lab light, against splotchy yellow scales. She’s silent. Sans huffs before he turns it into an easy-going laugh. 

"ah, sorry that about Alphys. i’ll buy ya another one later, ok?” Sans nearly sounds like his normal self. Alphys quivers, wiping a trail of snot from her snout with the sleeve of her lab coat. For a moment she had almost been afraid, afraid of Sans. "i've _‘bean’_ kinda stressed and i gotta _‘latte’_ on my mind.” The joke falls flat. 

Alphys can’t wrap her head around any reason that would make Sans want to act this way – like the situation is some kind of joke or he’s at a bad gig. 

The lizard sniffs, wiping her nose again. It still glistens. Her eyes are red and wet behind her glasses. Above them and the crowd, the TV whirls. A robotic voice echoes statically over the speakers and everyone’s heads turn up. Nearly every monster in the Underground recognises that famous voice. On screen, the human is about to fight a robot - Mettaton.

With a new humanoid form painted in a stylish shiny black and pink motif and a massive blaster gun blazing on his right arm, he’s a juxtaposition of glamour and deadliness. His armor and weapons look spick-and-span, fully upgraded and intimidating. Mettaton appears powerful and deadly as weapons gleam under bright spotlights.

The thrum of energy in the room is tense and soundless. Sans can feel monsters silently stirring around the Lab, daring to hope. A glimmering chance to stop the monstrous human has arisen in the humanoid form of the MTT idol. Mettaton is prattling on about saving Humanity and those who he needs to protect. As the robot goes on to explain his original function – a Human Eradication Robot – and how those functions were never truly removed, Sans can feel hesitant excitement permeate the room. Monsters are slowly starting to smile, being pulled in by Mettaton’s bolstering confidence. Hope spreads like an infection. The superstar has arrived to save the day.

The human appears unfazed though, washed-out and red-cheeked under the blaring hot stage lights. There is a calm intensity in its crimson eyes.

“It’s show time, darling.”

Sans knows what will happen. He turns his head away and looks to the ground. He can’t watch. 

He doesn’t hear the weapon strike, even in the hushed room, but he hears the quiet “Guess you don’t want to join my fanclub…?” An epic bang delivers the final news. The monitor shakes and the screen goes black. It was very quick at least.

The explosion is like a starting pistol for pandemonium.

The quiet faith snaps. Crying, screaming and panicking flood the masses; terror shatters the calm and fragile hope. 

Many monsters cry out in despair, others seem numbly accepting and several fans scream in horror. A particular admirer unleashes a high pitch wail that is quickly choked off. Fear spikes again, worse than before. The sight of their favourite star being murdered before their eyes sends them into a mass of terrified mindless creatures, swarming and pushing at each other. Cries of pain ring out, strangled screams of terror and the room collapses into an uproar.

Everyone is afraid. What chance did they have if a monster boasting the latest technology was killed so easily? The previous rush for the protection of the Lab hastily resumes, and there is almost a stampede.

Alphys, who is in charge, makes no move to restore order. She stares blankly at the high monitor, face pinched. Sans wonders how many monsters she has watched die? How many friends she has seen become little more than dust? Did she watch Undyne?

She had seen Papyrus.

He reaches over and Alphys shirks her head down, almost flinching until Sans touches the top of her head. He strokes it gently and it sends the scientist back many years. When she started working in the Lab, she was a nervous wreck, breaking things left and right. But every time Alphys dropped glassware, Sans would pat her on the head and make a joke. He had a cheerful tenor as he spoke over the gentle rasp of bone against scale. 

_"don’t even worry ‘bout it. i’ve broken a **‘skeleton’** of beakers before.”_  
_"everyone breaks something. this isn’t **‘shattering’** news.”_  
_"unless you’re hurt, the only problem is that it’s a real **‘pane’** to clean up.”_  
_"just stay **‘glassy’** , Al.”_

At first, it had been annoying to Alphys; it felt somewhat patronising. 

But later, it started making her laugh. Her stress would melt away. How could it not? Sans was great at making others laugh, giving them a bright spot in their day and making bad things seem a little less. He was a good comedian. He always tried to give people what they need - small bursts of happiness. It had helped her then, and it was helping her again now.

And maybe it is that little shred of nostalgic happy familiarity that finally breaks down Alphys’s resolve.

Her voice breaks.

“O-Okay Sans. If you think, you know what you’re doing… I’ll give you the last of the DETERMINATION I’ve extracted from the human souls.” There is bitter tiredness in Alphys’s tone. She sounds absolutely miserable.

His brother is dead; he must be hurting fiercely. So is Alphys. But she and Sans are both scientists - they both just need to keep moving forward. In whatever way that they could.

She gestures with her claw, a signal for Sans to follow, and moves through the bevy of monsters into the Lab at the back. The monsters split slowly like a cracking ice sheet, letting the two proceed relatively unhindered. Eyes full of admiration follow the pair and Alphys ducks her head. She didn’t deserve the praise; she isn’t a hero.

As Sans passes the entrance, he notices a ‘Washroom’ sign trampled on the ground which has fallen from the door. _'guess i ain’t the only one hiding a Lab.’_

Inside the Lab, the _true Lab_ , is even busier. Alphys has been hard-working, phoning and spreading the word of a safe zone, and many monsters have already gathered here. She guides him through rooms and hallways, passing little groups and packs of scared monsters that huddle in fear and observe them cautiously on their journey. Dust is kicked up as they go; cobwebs cover the corners, and grime coats the lighting making the Lab look grim and abandoned. The dim, humid hallways are filled with steam and crying monsters that meander hopelessly. Everything is a mess.

Finally, the scientist enters a large room with at the centre what could only be described as a behemoth. Sans stops and stares.

The thing is like a lusus naturae; massive and almost alive with two giant voids that appear similar to eyes. The machine hangs from the ceiling by large metal pipes. What could be mistaken for a toothless gaping jaw dangles over a pitch-black void. The thing, this metal colossus, is terrifying.

“Er, this is the DT Extraction Machine… I, um, b-b-built it based the p-prototype that you made. I don’t think you ever saw it this completed version – you, uh, moved to Snowdin.” Alphys sounds so unsure of herself. They are alone and Alphys doesn’t look him in the eye.

Sans nods. The appearance is radically different from the prototype. Though when he looks closely, he can spot designs that he made and machine parts that are inked onto blueprints back at his own secret lab. He sees Alphys’s tail disappear into an adjoining room, for a brief moment, before she shuffles out again.

Reluctance practically drips off of her, as she slowly holds out a large glass flask. Thick scarlet liquid swishes around in the flask, tinted dark at the centre. It looks simple for what it is. In fact, it looks a lot like ketchup. And there’s also a lot more liquid than Sans thought there would be. A huge syringe and needle are taped to the side.

He gently tugs it from Alphys’s claws and holds it high up above his skull to look at it better. In the shadowy Lab, it’s hard to see any detail – he barely makes out the scrawl of a label, “DETERMINATION – extracted from Yellow + Green”.

A real smile spreads across his face but it’s sinister. As Sans turns to look at her, Alphys flinches. He looks menacing, pupil-less eye sockets burrowing into her. "thank you. Alphys.” The scientist looks regretful, almost as if she is ready to burst forward and pull the flask from his hands and tuck it away somewhere safe and hidden. Sans conceals it away in his pocket before she has the chance.

Then he’s turning sharply on his heels. He’s got a human to kill.

“W-w-what is y-your p-p-plan, Sans?” Alphys stutters out behind him. She sounds terrified, but Sans isn’t sure of what anymore. The skeleton doesn’t turn and Alphys gapes at the back of his hood.

"i’m gonna fuckin' kill that thing obviously.”

“W-Wait, what?!” Alphys’s distressed voice calls out. “You mean the h-h-human?!” The skeleton still moves towards the nearest door. “You, you c-can’t! Sans! Please, stop!” The lizard is yelling now, but shock stills her feet. She’s heaving like she’s about to be ill. “I-I t-thought that you h-had some s-sort of i-i-invention!” 

Feet begin shuffling. Alphys finally finds her ability to move and her hands are reaching out. But Sans is already so close to the door. Just a couple of more steps and he’ll be walking right through one of his ol’ shortcuts. Alphys’s panicky heavy breathing is catching up. She is on the verge of hyperventilating, but Sans doesn’t, can’t, stop. She keeps begging and the tips of her claws almost catch on the edge of the skeleton’s hoodie, but he slips through the doorway.

“W-wait, San! Are you planning on i-i-injecting the DETERMINATION?! You can’t! If you do that, you’ll mel~! **SANS! Wait!! Wai~** ” Her cries cut out as Sans leaves.

Golden light fills the hallway. 


	4. Determination is one hell of a drug

**Summary for the Chapter:**

> Beta-ed and re-uploaded. :)

He’s holding his hand up to shade his eyes. Streams of light still fall through the gaps in his bony hand, blinding him. The hallway is a lot brighter than the Lab. He pulls his hood more forward to block the light. The flask of determination dangles from his other hand, sloshing.

He stares at the strange substance. It looks redder in the bright light. 

Fingers peel the syringe away from the side. It’s very large, heavy and made with glass; the gradient along the barrel shows that it holds up to 250cc. The journal entry he read used 150cc, what would happen if he uses more? 

The skeleton knows that it couldn’t be as simple as just injecting determination and then winning. The sudden introduction of a human’s intense DETERMINATION would probably have severe side effects and consequences on a monster’s SOUL. 

Sans briefly considers the possible risks – he needs the power, but it wouldn’t do for him to be unable to fight because of rashness. However, the anger buzzing between his ears makes it hard to justify true ‘caution’. He weighs the syringe in his hand, rolling it in his palm as he lifts it up and down. 200cc is a good compromise he decides eventually.

Watching it fill the syringe, feeling the drag of the thick crimson liquid, it fills Sans with a sense of apprehension. The DETERMINATION looks brighter in the syringe, tinged orange at the edges where the light hits. Sans lifts his sweater and t-shirt up, revealing a cream-coloured rib cage and his small SOUL – a dull white heart with the tip pointing skyward just like every other monster’s soul. The point of the needle hesitantly hovers over the SOUL. Then he presses in and injects.

The SOUL expands with the liquid, a fat drop of red dribbling out from where the needle had punctuated. There is an uncomfortable sensation similar to bloating - heavy and sore. It swells in his chest, burning with the stretch and becomes painful. Hot electric pain constricts his ribcage, making it hard to breathe and forcing Sans to gasp for air. The skeleton clutches at his chest, fingers pulling on his turtleneck sweater and stretching the white material. He’s too hot; the light shining through the tall windows scorches his bones. Heat is building up. 

Then the pressure whooshes out like a balloon popping, leaving behind something akin to downing 12 cups of burning coffee.

Sans is too warm. His body vibrates with energy, burning with zeal and strength. The stimulation of having DETERMINATION fill his SOUL makes it hard to stand still. Sans quells the urge to start pacing. It takes some twitchy shifting before the skeleton gets use to the sensation of coursing energy through his bones. The discomfort lessens slightly as the feeling becomes more and more familiar, and subtle perceptions come into focus. 

He drags his hand across his forehead. "whew.” He still feels hot, and now kind of… _‘clammy’_ Sans supposes. Skeletons aren’t affected by temperature though they can sense it - sweating and shivering are foreign concepts. However, the humidity clinging to his bones is how he would imagine perspiration to feel like.

However, that is nothing compare to the feeling of power he now has and how amazing it feels.

Sans wiggles his fingertips and feels power spark at the tips. Magic flows almost endless out of his soul and into his body. It course through his marrow like a tidal wave. His eye socket burns.

He stares at his reflection in the polished marble floor; reflected back is a skeleton with an eye burning blue and a grin wide enough to almost snap the skull in half. His eye, which normally glows yellowish-blue when he uses magic, is now a trail of blazing azure flame. His hood darkens his face and makes the blue look even brighter. Sans likes the image. _'heh, it even matches my jacket.’_

He flicks his fingers, calling forth more magic than he could ever have done on his own, and above his head a giant animal skull snaps into existence. It opens its jaw, twisting it head and snapping like a wild beast. Its dead blue eyes lock onto Sans and the GasterBlaster halts, waiting for orders; when Sans points, it unleashes a maelstrom.

An enormous blast of white energy hurtles down the hallway, smashing into the wall at the end. The cold heat of the attack sweeps up air and the resulting winds blow back on Sans, whipping up his jacket in a flurry of blue. As the air settles, the GasterBlaster fades. Sans is almost laughing. Bone fingers scrape against his mouth as he tries to quench the giddy giggles that threaten to burst out between his teeth. A heedless, un-smotherable grin paints his face; it would look dopey if not for the harshness in his eyes. The thrill of power is a heady feeling and it churns restlessly. With this power, Sans knows that he can easily kill that thing.

He waits.

* * *

_'#29_

_just took 200cc DETERMINATION. feeling kinda awesome._

_now, i’m gonna go **K I L L** that fuckin’ human._

* * *

A tiny silhouette emerges from the end of the corridor. It touches something briefly, before turning to the skeleton. It approaches until it is standing in a yellow beam of light, highlighted by an orange halo and smiling sweetly at Sans. The human is awash with gold, with a healthy pink glow to its cheeks. He hates that thing.

"s’up. you’ve been busy.” Sans is shaking - with fear, with excitement, with Determination. There’s a vehemence building behind his grin and a surge of blood thirst. 

“No scarf this time? I keep saying how excellent you look in red.” It reaches into its pocket and pulls out a short sharp knife. The blade glints, but the handle is dusty. “Though in all honesty, this is a much more familiar sight.” Its grin curls up at the edges.

Sans can feel heat and pressure building up inside his skull. His ribcage heaves obscured his heavy coat, and it feels like he’s breathing in burning ashes. His tongue is dry. Dark eye sockets just gaze at the human, eerily watching, and he smiles widely. The thing is waiting for his reaction.

His eye explodes into pale cobalt fire. "let’s just get started then?”

Sans obtains the pleasure of watching the human’s utter surprise at the short and immediate intro into the fight. He didn’t know what the other Sanses were doing but he personally didn’t see the point of waiting around. 

The glee only increases when he sees the expression morph into gobsmacked as 3 GasterBlasters materialise. Cold, raw power slams into the thing. He’s almost laughing as the shock transforms into outraged pain, red eyes lighting up and glaring straight at him. The human turns to dodge but Sans isn’t finished yet. A barrage of bones rain down, gravity twists and turns, and the full force of it bombards the human’s SOUL. The chaotic spray of magic assaults the little red heart and its HP is tumbling away quicker and quicker. Karma finishes the job.

There is a tiny gasp. Shaking with its small back curved back like an arching bridge, the red SOUL heart hovers above its chest trembling to hold itself together. _Crick!_ A crack splits down the centre of the heart and with a snap, the rest of the SOUL shatters, the red fading into the warm air.

* * *

The human lands with a quiet thud, the SOUL ruptured and destroyed. 

"welp, that was a _‘blast’_ , human. don’t come back tho’.”

The trembling in his ribs bounces his jacket and the items inside jiggle. That had felt even better than he had imagined. The skeleton eyes the unmoving body of the human, face down and knife still tightly gripped. He leans forwards and nudges its head with his slipper. It doesn’t twitch and Sans breathes a sigh of relief. 

It is finally gone. Bony fingers fish out the journal and his blue novelty pen. He adds another, and final, score to the tally - six fights until the human died and stayed dead. Even with all that LOVE, its little red SOUL was no match for Sans’s ire fuelled attack and so far it had no even managed to survive the first move.

The human is dead.

Staring down at its corpse, Sans is suddenly struck with inertia as he realises he must now decide what to do next. Papyrus is gone, so are most of his friends, and he cannot see any point in hanging around Snowdin anymore. The skeleton sways, over heated with exertion and DETERMINATION, as he suddenly finds himself lost once again, purposeless. Sans wipes his forehead again, trying to get rid of the sticky feeling coating his too hot bones. It is worse than before the fight.

As he draws his fingers away from his skull, strands of thick white tar trail after his fingers. Sans’s eye sockets widen at the strange heavy stuff before more white sludge starts dripping from the crown of his head and into his right eye. He tries pushing it up his other hand, the journal falling to the ground with a thump, and he feels his skull flex and bend under his fingers like a soft sponge. Birds in the distances echo around the columns, muffled like he is under water. Heavy, heavy panic fills his mouth and he’s shaking, watching his fingers tips melt and drip like candle wax before his hindered eyes. The heat and horror keeps building and building and building…

Sans closes his eyes, shutting them tight. 

After several heartbeats, he can still hear birds chirping just outside the tall windows, clearer and sharper. The skeleton slowly opens his eyes; his hand is high above his head blocking streams of light. It appears whole, hale and healthy; the bone is shiny, smooth and completely hard. The heat still simmers in his chest but it’s cooler. 

The skeleton blearily blinks and looks around in mild confusion; his head is stuffy like he just woke up from a deep dream. Memories of melting bone and dead humans are already fuzzy. He pulls at the figurative cotton wool filling his mind, staring at the dropped journal splayed on the floor. Six blue tallies sit against the cream page. He gingerly picks the book up and stares at the page. 

Footsteps echo and Sans knows that it’s the human back again for another fight.

He looks up, tucking the book inside of his jacket.

"wow. you look pissed.” Sans smiles as the human steps into the light. The human’s crimson eyes narrow, its jaw tenses and teeth grit. The round cheeks puff out in an irritated pout, and it seems to bite its tongue to stop whatever venom it was planning on spitting back. 

Instead it quietly hisses out a question.

“Why?... Why are you acting like this?... You _never_ change.” Its knuckles whiten as its grip tightens around the knife’s handle. “You are supposed to not care. You aren’t suppose to actually _try_.” It spits out the last sentence. “What happened to your apathy, Sans?” There is a genuine curiosity in its voice, hidden behind the frustration tainting its tone.

"dunno. maybe i’m just different from those other Sanses.” The skeleton shrugs. The human looks unamused at the answer. "seventh time is the charm, though. maybe, i’ll get lucky and you’ll finally stay dead.” Sans points his left hand, flicking his wrist.

GasterBlasters appear and the fight begins anew.

* * *

The fight ends with a half-choked scream of frustration. The SOUL crumbles into nothing.

Sans draws in the tenth tally with a tightly gripped pen. He almost rips through the thick paper. The human had finally survived to the second attack. Its irritation as its HP ticks away to nothing is satisfying but Sans has difficulty focussing on it. 

Rather, he is concentrating on the cloudy memories that he could retain from previous fights. Or rather, after the end of the fights. 

The skeleton collapses into a heap of warm bones and carefully flicks back several pages in the book. He feels a slick drop slowly move down the side of his skull but ignores it. 

He scans a long entry about a Sans who had a very _bad time_ in his timeline. Human DETERMINATION is too strong for a monster’s body. A monster’s body is basically just dust held together by magic; it cannot contain that much DETERMINATION and maintain its form. The power overloads the SOUL. In turn, a monster’s magic and in extension their body, begins to collapse into a form more suitable for containing the energy. 

Long story short, Sans is going to melt.

Crazy, right?

He turns a page and starts reading a different timeline. This is an even crazier entry, theorising about the existence of two SOULs within the human. It ends with a wild note about the possibility of two different humans sharing one SOUL and one body.

Chara and Frisk.

He recognises both names, from different timeline entries. Honestly, Sans is wishing that he had stopped to at least skim the journal before this rage-fuelled self-righteous crusade against one lone human. There is a lot of important information scattered among the pages – mostly as footnotes or tips. 

He focuses on the names until a tingling sensation crawls up his spine and he’s once again squinting into the familiar light.

* * *

It was like remembering a dream; the memories are distant, ill-defined and jumbled. _But still there._ Sans realises that his attacks are becoming somewhat predictable. He has no idea how to change this. His memories would only crystallise after the attack, and by then it is too late to alter anything. This is only his third attack.

It is exhausting. He is exhausted, despite all the energy vibrating inside his SOUL.

That’s the thing about anger; it tires you out. A lot. Sans has spent most of this day angry, and now as he fights, he is just too tired to be angry anymore. 

He dodges the knife’s strike with ease.

Sans raises his left arm in preparation for his fourth attack and watches the human SOUL dye blue and soar upwards like an eagle. Bones tumble into existence but despite the inversion in gravity, it avoids most of them. Karma slowly leeches at their HP. It is low, this battle will end soon and judging by the grunts and snarls, the human knows it as well. 

The human lands on its feet, stumbling forward to catch itself on its hands. It pushes itself up with a violent thrust; its arms click with the movement. The human’s scarlet eyes are still flat - though the tilt of the mouth and eyebrows suggest annoyance. It raises it arm as if to attack, but the hand trembles in the air. The human grits its jaw, showing two rows of clenched white teeth, and seemingly struggles to lower the appendage. After a couple of tense seconds, the human sucks in a deep breath and releases it slowly. The hand slams down and the knife thrusts forwards.

Sans side steps it, his rib caging rumbling with warmth. The strike was not even close this time.

He stares at the human. There was hesitation in the last attack – it was slow, sloppy and poorly aimed. The thing seems more aggravated than before. Two names from a book cross his mind.

Frisk and Chara.

He pauses before his next attack and actually looks at the human. It’s panting, low on HP and slowly losing a battle with its own temper. But he can see an internal struggle in its eyes like it’s pushing itself to even face him like this. Red eyes flicker between emotion and emptiness. 

Two people sharing one SOUL? That was the stuff of tall tales. Then again, so was a time travelling human with a violent deposition towards monsters. 

His burning eye brightens and the human hurtles across the room like a blue comet. They hit the wall with a thump. Gravity changes again. The SOUL makes a sharp left, heading up and brushing by a line of bones, and almost crashes into the ceiling before landing on top of the stain glass window. As the human steadies itself, forced against the window by its blue SOUL, Sans sees its reflection. Rather, he sees both of its reflections. 

One body, one SOUL, _two reflections_. 

One stands tall, staring down at the skeleton. Its posture reflects the physical body of the human, though both reflection and body impossibly face him. Its emotionless face promises pain. The reflection’s appearance is different from the real body - reddish brown hair, pink blush and a green and yellow sweater. The other one, hunched and small, is standing half hidden behind the first one’s shoulder. Only a crown of brown hair and the edge of a purple jumper is visible. It is turned away in the reflection, as if it can’t bear to meet Sans’s eyes. A heavy realisation sets in.

The gravity suddenly switches and the human plummets. 

* * *

The human is _sparing_ Sans.

The skeleton could almost laugh. It’s standing there, knife abandoned on the floor, with its tiny arms spread wide. Tears streak down its face, cheeks ruddy from crying. The skeleton can still see the fight in its eyes though, and he still remembers those two names. More importantly he can remember two reflections; surrounded with gold and tinged yellow from the bright light, the image of two humans was reflected in the stain-glass windows. The memory had haunted him through the last 3 fights.

"you think ya can just spare me?”

The thing nods. There is DETERMINATION searing in its eyes. It has made a decision. Why didn’t it show _this_ mercy to Papyrus? Tired, burning anger reminds Sans why he is here. 

"well, ya didn’t spare my brother…”

Bones crunch down and the SOUL shatters. The resolve only leaves the human’s eyes once the body slumps forward.

**"so get dunked on!”**

* * *

They go back to the beginning. They RESET everything and make the timeline and every mistake disappears.

* * *

_'#29_

_just took 200cc DETERMINATION. ~~feeling kinda awesome.~~_

_~~now, i’m gonna go **K I L L** that fuckin’ human.~~ _

_don’t take that much DETERMINATION. you’ll melt and nobody wants to clean up that mess, buddy. if i was you, and i am, i would just trust me and not do it._

_important - there are two people inside the human’s SOUL. look at its reflection. **Don’t Forget.** ’_


	5. love-less

**Summary for the Chapter:**

> It's just a short transitional chapter from Chara's POV. I had some difficulties writing this - I didn't know how much I wanted to reveal. Sorry for the long wait anyway.
> 
> A new time loop starts next chapter.

Chara’s eyes always look dead - no matter how many smiles and giggles they force out. They try forcing emotion into them, tries making them look alive, but they were dead because they are dead. Chara has no SOUL and, like their brother, has no emotions. Or at least no joy. _No love._ And doesn’t that just kill them? (Haha.)

So they kill others instead, chasing the joy of taking life and playing God. And Chara grins while doing it. They might as well _look_ like they're enjoying themselves, as they steal lives again and again, stuck in this endless limbo. The loop continues and they pretends that the grin soaked in madness is becoming more and more real. 

It hurts Frisk.

Frisk can _feel._ They feel happiness and love and all these happy sappy emotions that Chara can’t help but think as ‘stupid’ now. Frisk glows with these emotions like a fountain bubbling with light; they overflow from their SOUL. The dead child can only deal with bitterness, anger and apathy. Frustration simmers as Chara realises that love is only a memory for them.

And Chara thinks _'Isn’t that unfair?’_

Then they kill and Frisk feels more pain. Frisk can feel that as well - they can feel sadness, anger, regret and all sorts of aching emotions. The two children are the same in this respect. Chara exploits that endlessly. They refuse to admit to that occasional twinge of jealousy that sparks whenever Frisk seems happy. Chara reasons that only an idiot would be envious of Frisk. 

However, sometimes in moments of consuming emptiness, Chara irrationally thinks that with enough pain and DETERMINATION, they might RESET all the way back to being alive again. It a foolish idea, _barely a plan,_ only formed in the rare moments of giddy desperation for a SOUL. They wonder if they will feel love if they have a SOUL again. Will they feel… happy? 

Impossible. Demons do not feel ‘love’. At this point, Chara is unsure if she even wants to love ever again. 

Chara has a different plan. _A better plan._ The soulless child holds it close to their chest, hiding it from their partner. Frisk knows snatches of it, but they don’t know the end game – the True Goal to this homicidal rampage. She is Determined to finish it; Frisk is Determined to stand in their way.

The two children’s discord has twisted time into a broken record frozen on replay. And there are only one ending to this ceaseless loop– one of them must _lose._

It is a battle of will power. Their now unwilling partner who they share this unending existence with believes that ‘their’ DETERMINATION will be enough. Chara laughs loudly at that, mocking Frisk. It’s fruitless. Astriel had refused to help them long ago; Chara won’t let Frisk refuse now. Together they will finish what Chara started. Chara knows how to force their partner to bend to their rule. They will break Frisk and end this eternal cycle.

Chara has nothing left to lose. Frisk has everything.

Frisk is too kind, pointlessly so. Their partner’s altruism and perfectionist attitude is what will ultimately be their downfall. Or at least that is what Chara believes.

And so the first child goes forth, methodically destroying everything and everyone that belongs to Frisk. Friends, family and allies – they all turn to dust under a child’s hand. Chara has realised that whining and wishing will change nothing. If they want to achieve their ultimate ambition then they has to complete their route. They must be Determined. They must take action and keep moving forward. **No Mercy.**

At the end of this genocide, they know Frisk’s HOPE will shatter.

Frisk will finally fall into despair. Their DETERMINATION will crumble once they lose everything. This new fallen child will be powerless. Chara waits for this timeline impatiently. However... One last idiot stands in Chara's way, always defeating them.

Chara _hates_ Sans.

Love is beyond Chara but loathing is as easy as breathing. (If they still breathed.) That damned comedian always stops them at the last stretch. He gives Frisk HOPE. And as fun as it is to torment the skeleton, he is just one more hindrance in the way of their perfect completion. Once they finally kill Sans, there will be no grin. There will just be a blank face and familiar dead eyes as they stare coldly ahead, waiting for the triumph joy of finally winning. It will never come. After that, Chara’s plan will move forward into the final stages.

So Chara decides to try again. 

They _must_ kill Sans.

.  
.  
.  
.

Too bad that Chara's temper makes them lose control of the SOUL and lose control of the situation. Their frustration at never beating Sans is their downfall. When that happens, Frisk forces them to RESET. They go back to the beginning of this futile cycle. So once again they must fight for control and once again Chara must kill **E V E R Y B O D Y.**

.  
.  
.  
.

“He changed, Chara…”

“No, he didn’t. Sans never changes. No one does. And even if he did… Well, I won’t let _that_ happen again.”


	6. Human captured?!

**Summary for the Chapter:**

> I got exams soon so it'll be a while until this updates again.

He watches Papyrus rush off, after the tall skeleton emits a puzzled laugh. All afternoon, his brother had been grinning and laughing. His loud voice had boomed with joy as he explained puzzles to the human. He had been practically jumping with glee, bones rattling loud and proud. 

It’s been a while since Sans has seen Papyrus this happy.

Recently, Sans had been noticing that his brother has been feeling kinda down, which worried him. If his brother, the coolest most optimistic monster he knows, can’t stay full of HOPE, who can? 

Though, with feeling unrecognised, not qualifying for the Royal Guard again and Papyrus’s clumsy attempts at friendship, it was no wonder he had been feeling blue.

His younger brother always puts other monsters before himself, meddling in affairs and appearing pushy. Other monsters normally don’t know how to react to a tall, over-enthusiastic skeleton, creating a rift between Papyrus and others. Then Papyrus tries harder, pushes more, and only finds himself more alone. 

It left Papyrus focusing more of his energy into trying to make Sans happy instead, overcompensating for his own blues. Sans thinks it should be the other way around.

Pap is responsible for keeping him on the _‘straight and narrow’_ as the taller skeleton would proudly proclaim. He seemed to be getting more and more annoyed at San’s apparently growing laziness. 

The younger skeleton even convinced Sans to go out and find some odd jobs to do around town; selling hotdogs and doing the occasional gig at MTT Resort. In the hope that giving Sans some kind of purpose, to work towards, to distract, would make him happier again. When that didn't seem like enough, Pap had went as far as somehow managing to persuade Undyne to give Sans a Sentry post. That was the kind of selfless monster Papyrus was.

Sans knows he isn’t always the best brother but he tries. Honestly, it sometimes feels like he needs Papyrus more than his Lil’ bro needs him. Sans often pondered on how unfair it was to Paps. Papyrus shouldn’t be worrying about his big brother; he should be focusing on making himself happy. And it was San’s job as the older sibling to help out.

Luckily the human had showed up this morning. 

Shaking hands, giggling at the old whoopee cushion gimmick and his bad puns, the human seemed like a friendly guy. Sans had felt no hesitation in introducing them to his lil’ brother. The human dutifully listened to the entirety of his brother’s rambling and attempted the puzzles with all of their SOUL. Each puzzle was solved fully, though with strange familiar ease. They seemed determined to help Papyrus have some fun, playing along while hiding small smiles behind purple sleeves and muffling laughter into tiny hands. They were a little ball of quiet cheer if a bit nervous and twitchy at times.

Papyrus may have been down lately but doing puzzles all day with the human has cheered him up. Honestly, Sans was having fun as well. Especially when his brother had revealed that last puzzle, decked out with fire, spears, a cannon and even a tiny white dog. He didn’t think that Pap actually had it in him to set something like that up. He was impressed.

However, Sans hadn’t been worried about Papyrus actually activating that last puzzle – it had looked like a real challenge for even Undyne but his bro wasn’t the type of monster to force someone to do something dangerous. Though the human couldn’t have known that, they had also seemed unconcerned.

Now, the human disembarks from the long rope bridge and shyly approaches him. They look up at him almost expectantly; tilting their head and making short chestnut brown hair sweep sideways.

"s’up, kid. thanks for humouring my brother.” Sans grins and shoves his hands into his pocket. The human still seems calm considering that death trap that had hovered over the bridge mere minutes ago. "i don’t know what my brother’s going to do now. if i were you, i would make sure i understand blue attacks.” They give a small nod in understanding but remain in front of him, staring. Sans glances away briefly, wondering what they are waiting for. When he looks back, they are still staring at him with shiny red eyes. It is the first clear look he has got of them, they were always shyly hidden behind short lashes. It wasn’t a startling colour for a monster, but it looks almost unnatural on the human. Not that Sans would know what eye colour humans were supposed to have..

After a few moments, the human frowns, pouting their lips. They rub their arm nervously and break eye contact to stare at his slippers. “Um. Do you remember?...” They ask in a low voice, almost anxiously.

"ya gonna have to be more specific, kiddo.”

There is a pause before they force out a beaming grin. They hold out their hands jazz-style. “That joke about the amessiac. I forgot how it goes.” They mispronounce amnesiac but the joke still hits off.

Sans lets out a surprised hearty laugh. He hadn’t expected the first human he would meet to be a comedian. "heheheheh. yep, that one tickles my _'funny bone'_ , kid. real _'punny'_.” The human smiles genuinely now, pleased.

"Skele- _pun_.” They point out Sans’s pun, happily jabbing a short finger at him.

The skeleton grins back. He has heard these jokes before but they can still make him chuckle. He ruffles their brown mop of hair; it’s soft and smells like grass and flowers. Brown tufts of hair stick out in different directions. Two particular loop-sided tussocks look like dog-ears. The human squeaks in surprise and tries taming the mane that Sans has messed up.

"my brother only likes his own puns. he says i overuse mine. that wasn’t half bad tho’, pal. ya might make him laugh with that one.”

The human hums happily, thumbs up in agreement. They give a small goodbye wave before skipping off towards Snowdin, after Papyrus. The human only glances back once; their expression is a strange unsure mixture of melancholy, acceptance and determination. Sans is placing a lot of trust in the human’s hands; he has faith that they will not hurt his brother. They seem affable enough, a little too quiet and quirky, but everyone have their own little oddities. Sans has confidence in the human to do the right thing. 

Slinging out a bottle of ketchup from his hoodie’s pocket, he starts drinking it and takes a ‘shortcut’ back to his workshop. He wants to take a quick look at those time reports again before heading out to Grillby’s. He’s pretty sure that the human is the cause of the time anomaly but checking the recent temporal activity again won’t hurt. If the human is the source, maybe befriending them will cease the time fluctuations. 

He places the half-empty ketchup bottle on top of a blueprint and wanders down the workbench to a stack of papers, several centimetres thick. _'ugh. i remember it being smaller. welp, i guess i’ll flick through the first couple of pages and deal with the rest… some other time.’_

He lifts up the first page, showing staggering black and blue activity lines across a graph, and stares at the book revealed underneath. Not a book that was here last night, or a book that he recognises. It looks almost like a traditional diary that had strangely gotten muddled up among Sans’s raw data.

Bone fingers gently lift it up from its resting spot, feeling the odd weightlessness and the soft texture of worn black leather. There are stains on the corners of the cover, which look similar to water damage. The skeleton slowly unwraps the twine that holds the book closed. Turning to the first page, he is surprised to see a messy cipher and his neat curvy writing printed across the paper. Then he is flabbergasted at what the writing says. 

It’s a message that speaks of other timelines and time loops – concepts that are mere theories from Sans’s study into temporal space.

The name at the end is unfamiliar, though.

"Dr Gaster?”

A time traveller? And more importantly, the possible owner of a time travelling journal that might be from the future. It was almost too good to be true – a book that just somehow magically proves other timelines and time travel. In fact, it is too good to be true.

He flicks forward a few pages until he comes to pages dominated by his own handwriting again. The first entry starts off brutally. 

_ 'Pap is dead.  _

_ that brother-killing human has fled to the Waterfall. _

_ i’m currently crashing at Alphys’s ~~‘cause i don’t want to go home.~~ Al’s been filming the human, still is, and i have no idea why. honestly i wish she would just stop. ~~i don’t want~~ _

_ she has the whole thing set up to a huge monitor. it looks like the human is freaking out or something. they keep fleeing from any monster they encounter – like they are terrified. (of what? i don’t know. certainly ain’t the monsters.)  _

_ they are nevertheless moving forward. it’s like they’re on some sort of mission or something. ~~i can almost respect tha~~ it’s **sick.** _

_ Pap’s the kindest monster i know; there was no reason to... ya know. still wondering why they decided to kill **my brother**? they have spared other monsters. _

_ why is did **he** have to die?! _

_ ~~...was it something i did?~~ _

_ i suppose that ain’t really fair... after all, 4 other monsters are also missing and probably dead. this whole situation is a damn mess. _

_ i can’t help hating this human. i almost want them dead- Pap would probably be disappointed in me for thinking that. lucky for the human, i made a promise and i ain’t in the habit of breaking promises. _

_ and on top of everything, i find **this** book! full of coded notes from some Dr Gaster. i’ve started translating it. wow, what a sick joke! ~~whoever the fuck came up with it has a fucking bad sense of humour.~~ _

_ from what i can interpret so far (‘cause it ain’t exactly legible), this Doc might be a “time traveller”. ~~if he is, then why didn’t he save Pa~~ _

_ okay, look. i’ve been aware of multiple timelines for a while now; i even got readings and scans of these ‘time-jumps’. never been able to prove it - it’s just raw data and energy readings - and i need solid evidence.  _

_ i haven’t been interested in finding any evidence either. who would if it means proving that everything that you do is pointless? because it could all be reset? _

_ this whole mess is like some sort of sadistic joke and i’m not laughing at the punch line. _

_ i’ve been blue for a while, wondering about this possibility. ~~i think even Pap was beginning to notic~~ it’s hard knowin’ that any progress i make can be erased. i might have proved my theories a hundred times over but it could all be gone on some human’s whim. my brother could be killed again and again on **some human’s whim**. it’s pisses me off. _

_ and i can’t even stop them. _

_ this all feels... **inevitable.** dunno if that makes much sense or not. _

_ so why not give up? _

_ ... _

_ eh, well, i’ve been prattling on too much. Alphys is starting to glance over. i don’t even know if this journal can do what it claims - i guess any future Sanses will attest to that. human’s ‘bout to fight Undyne and i don’t really feel like watchin’. _

_ i’ll see them before they talk to Asgore. _

_ **if** they survive Undyne.’ _

Sans reads through the passage, tensely gripping the page. It’s full of sad frustration and anger that ultimately ends in apathy. There’s reluctant indifference as he, this previous Sans, realises that his brother is dead and it was apparently _‘inevitable’_.

There’s a ringing in Sans’s skull, high pitched and echoey. His skull feels stuffed with heavy snow, making everything around him muffled as if through a filter. 

He almost misses the quick messy scribble at the end, smudged from being hastily written. It seems to be written only moments after the previous sentence.

_'the human just made this weird hand movement. i think they are gonn-.'_

The statement ends abruptly and Sans can only assume that the human RESET that timeline.

Then cold panic seizes Sans’s SOUL. He had left Papyrus alone with the human! He fumbles around, calling up frantic magic and almost drops the book, juggling it clumsily. He pitches forward to catch the journal before it falls, balancing on a shaky bone leg with the other extended behind him. As soon as the book in his bony grasp, he’s taking a rushed shortcut, not thinking clearly enough to right his own balance first.

He appears in his own bedroom, off-balance and stumbles skull first into the whirlwind of rubbish. He gets smacked in the face with a greasy napkin and flails backwards, finally falling onto his bottom. Sans pulls the napkin off and throws it to the side. He rolls to his knees, bones clacking, as he hurries to his feet. Fears swallows up most of his senses. The entire world blurs out of focus around him, pinpointing clarity on the door. There is a mantra running through his mind, begging that Papyrus hasn’t fought the human yet, that his baby brother is still safe. He yanks the door open and crashes onto the landing.

**“BROTHER!”**

Sans is panting as the voice echoes around his skull and the world around him becomes clearer.  "YOU ARE BEING VERY RUDE TO OUR HOUSEGUEST!!” He leans over the landing’s rail and sees Papyrus below, arms crossed and glaring up at him. "HOW AM I MEANT TO BE ON A ROMANTIC DATE WITH THE HUMAN, IF YOU ARE INTERRUPTING IT? HONESTLY, SANS, THESE HIJINKS ARE NOT APPRECIATED.”

Sans stares dumbly at the scene downstairs. 

The human is sitting on the sofa; their legs swinging on the edge and feet dangling high above the ground. Papyrus is standing by the seat beside them, tapping a boot on the wooden floor. On the human’s lap, almost swamping their lower body, is today’s newspaper with the puzzle page open. A glass of milk sits by the human on the armrest. They have a milk moustache and a bright smile. They give another small, shy wave up to him.

They seem so innocent.

Sans doesn’t trust them.

"yo bro. i thought you were out capturing the human.” Sans props his head up on the railing, smiling easily. "and what’s this about a date?”

A pale blue blush appears on Papyrus’s cheekbones. He stamps his foot down. "I, THE GREAT PAPYRUS, _HAVE_ CAPTURED THE HUMAN!" He points a red glove at the human.

Sans glances towards the human who is giggling wildly, holding up a sweater sleeve to their mouth. If this is an act to make him drop his guard, it’s a good one. "doesn’t look captured to me, bro.” He replies easily enough, tamping down on any obvious wariness. He tries not to glare in suspicion at them, looking for reasons to doubt this human.

 ** _“AHA!”_** Papyrus grins in triumph.  "FOR YOU SEE SANS, I HAVE CAPTURED THE HUMAN’S HEART INSTEAD!” He places a glove on his chest proudly. "AND AS WE SPEAK, I AM ON A DATE WITH THE HUMAN. WE’RE ALREADY HALFWAY THROUGH THE JUNIOR JUMBLE.”

Sans laughs. Only his brother would think that solving newspaper puzzles would make a good date. Well, Pap wouldn’t really know any better since this is his first date. His eyes slide back over to the small human, and they meet his gaze with surprising openness. He stares intensely for a brief moment, trying to penetrate pass the possible lies and see their deception. Any secrets behind those red eyes remain elusive. There’s an itch at the back of his skull - like a warning. The human’s mask is perfect but a rumbling in his gut is telling him to be wary, to learn more.

He decides to drop his inquisitive stare. Sans worries about tipping the human off - if they knew that he possibly knows the truth, what would they do to Pap? Sharp fear claws the inside of his ribcage as he considers what may happen to his younger brother if he makes a mistake here. His SOUL is cold. Papyrus is too innocent to have such a horrible fate hang over his head.

He spares one last glance at the human, and feels frustration at how unassuming they still appear. The tiny creature seems as harmless as they did earlier - and he could sense no ill-intent. It’s infuriating that the only evidence for their malice is in the pages of a battered journal. 

Sans sighs internally.

As long as Papyrus is having fun, and the human doesn’t hurt him, it should be fine to leave them alone. At least, for now. It pains him to go. "welp. i better not get in the way. i don’t want to see you two kids _kissing_.” He winks and Papyrus’s face explodes into a deep blush. The human tilts their head almost quizzically.

"SANS! DO NOT SPEAK OF SUCH _VULGAR_ THINGS IN FRONT OF THE HUMAN. WHY I NEVER-“ Papyrus’s tirade is cut off as Sans closes the door to his bedroom. He’s almost too scared to leave them alone, but he needs to know more.

The skeleton leans back against the smooth wood of his door, slowly breathing in and out. His knees shake slightly and he slides to the ground. Sitting cross-legged, against the door, Sans tries to calm down. The human did not seem particularly violent or malicious. The fellow was the same as earlier; quiet, unassuming and pleasant. They appeared more friendly than dangerous. However, Sans knows that looks can be deceiving. If they are dangerous, Sans won’t let this human hurt Papyrus.

Sans pulls out the journal and begins to read.


	7. Ice to see you again

"GEEZ, MY BROTHER IS ALWAYS MAKING JOKES.” Papyrus states stormily, glaring up at the door Sans has disappeared behind. "WHENEVER HE’S NOT SLACKING OFF, HE’S UP TO THESE SHENANIGANS. IT IS MOST _INFURIATING_.” The skeleton turns back to the tiny human occupying the sofa, with a bright grin. Papyrus is always a wide range of shifting emotions – he could rarely stay angry or upset. 

"OH, HUMAN. YOU DRANK ALL OF YOUR MILK! NEVER FEAR, AS A BRILLIANT HOST AND DATE, I SHALL REFILL YOUR GLASS!”

The tall glass is snatched up, and the skeleton practically prances into the kitchen, boots clopping on the wooden floor. Frisk waits a moment before stilling their swinging legs and moving the newspaper to the side. Pushing off of the sofa, they land softly on the floor and trails after Papyrus. When they turn into the kitchen, they meet with the sight of Papyrus trying to wrestle the milk bottle out from behind stacked tubs of spaghetti crammed tightly into the fridge. His big red mitten hampers his process, making it difficult to navigate through narrow gaps without knocking the tuber-ware down. He mutters under his breath.

 ** _"AHA!”_** Papyrus cries out in triumph, and thrusts the bottle high into the air, signalling his victory over the over-filled fridge. When the tall skeleton turns, he finds his long legs tangled up around Frisk, who had quietly approached him. The two stumble, Papyrus frantically trying not to step on the human and Frisk fumbling to get away before someone is hurt. The pair starts to topple over together in their confusion. As Papyrus crashes, he throws his hand out in a panic. Blue magic grips Frisk’s SOUL; the child finds themselves whipped up into the air with such velocity that the breath is pushed from their lungs in a gasp. The skeleton hits the ground, landing on his back with clattering bones and a soft _oomph~_ He looks up and sees Frisk hovering safely in the air; they slowly spin with their legs starting to tip over their head. Thick eyebrows are drawn together in surprise; a small pink mouth hangs open as the child’s brain races to catch up with what just happened.

Papyrus is just happy he didn’t fall onto the tiny thing. He might have hurt his date if he hadn’t been as quick as he was. 

"OH WOWIE! I THOUGHT I WAS GOING TO LAND ON YOU, HUMAN! I’M NOT SURE ABOUT ETIQUETTE BUT I’M PRETTY CONFIDENT THAT YOU ARE _NOT_ MEANT TO LAND ON HOUSEGUESTS.” Papyrus sits up, grinning at the human as they try to right themselves mid-air.  "THANKFULLY MY BATTLE BODY PROTECTED ME FROM THE FALL.”

The human and monster make a strange sight together. The wiggling child waves their arms and legs wildly, flailing like a drunken bird, as they try to control their orbit, and the tall skeleton is sprawled out on the floor, long bones knocking against the tile as Papyrus does an amazing impression of a doormat.

The hilariously bizarre scene is just so unexpected – Papyrus normally has the balance and grace of a gymnast. Frisk dissolves into a string of bouncy giggles, curling up and clutching their sides. They are completely upside down, chocolate hair hanging and swaying with the laugh. Their cheeks bloom into puffy red splotches as Frisk gasps for air. But the giggles continue.

They hear Papyrus loud laughter join in. "NYEHEHEHEHEH!” Frisk doesn’t know if it’s become of the utter ridiculousness or if Pap was just happy to hear the human laugh so hard. 

It just feels good to laugh.

Papyrus turns to pick up the milk bottle but instead finds a growing puddle of white and the remains of a glass bottle in the centre.

"I DID NOT CRUSH YOU, HUMAN, BUT I HAVE DROPPED THE MILK.” The skeleton frowns briefly, staring down and shoulders slouching in disappointment. Frisk’s amused laughter dies off quickly. They sink slowly, dipping with the skeleton’s mood, but don’t touch the ground. The child futilely reaches out trying to touch Papyrus and offer comfort, short fingers grasping at empty air. The skeleton grins moments later; sadness brushed aside. He turns a 1000-watt beam towards the human, smiling brightly with shiny white teeth. "THANK GOODNESS MY BROTHER ISN’T HERE. HE WOULD SURELY MAKE SOME UN-CLASSY PUN ABOUT THIS _PARTICULAR_ SITUATION.” He speaks jokingly, trying to brighten up the atmosphere again.

“Sorry…” The shy apology comes out as a strained whisper. It seems reluctantly ripped from their throat in an accidental rush of regret.

Papyrus almost frowns again. The human’s voice drips with remorse; peculiar since the whole incident had been a tangled mix of clumsiness and accident. The only real casualty was the milk. The tall skeleton has a strong, inexplicable feeling that he is missing some important detail here. Papyrus almost wishes that his brother were here; he would probably see the cause of the human’s unexpected guilt. 

Sans is always much better at noticing these sort of things.

It might even be worth the _unbearable joke_ Pap knows would happen if he could make the human smile again.

Frisk sinks to the floor as the blue magic fades; their shoes land softly, touching tiles not covered in milk as Papyrus springs to his feet. "NEVER FEAR, HUMAN! THIS CHALLENGE WILL MERELY BECOME ONE MORE OBSTACLE TO DEFEAT IN ORDER TO BECOME A ROYAL GUARD!” He grabs a yellow dishtowel and tosses it onto the spillage. "IF YOU STILL WISH A GLASS OF MILK, WE CAN GO OUT AND BUY MORE!"

The human merely shakes their head, face dipped towards the floor to hide their red eyes. Papyrus doesn’t understand. Clearly the lack of milk is not the issue.

Papyrus tries again.

He places a gloved hand on the top of their head, comforting them. "IT IS NOT YOUR FAULT, HUMAN. I SHALL IMPROVE MY BALANCE MORE NOW THAT I KNOW IT IS LACKING PROFICIENCY. IT WON’T BE LONG UNTIL UNDYNE DEEMS ME READY TO BE A ROYAL GUARD!” The human looks up and matches his gaze.

Frisk gives a thumbs-up, with an uneasy smile. It seems enough to satisfy Papyrus, who replies with another glowing grin.

Papyrus cleans. The milk is quickly swept away with a familiar ease of someone who’s used to cleaning such messes. 

In the minutes that the skeleton is busy, Frisk meanders back into the living room again. They stare up at Sans’s room, pondering on his earlier interruption. It was different again. Normally, he bursts in with a trombone or a pun. They don’t know what to make of it, but a small hope blossoms in their chest. Frisk carefully wonders if perhaps this Sans does remember after all, and smiles optimistically at the thought.

_‘He never remembers, Frisk. You know this.’_

_He promised…_

Frisk shakes their head as if trying to dislodge the thought, brown hair fluffing up at the furious movement. Papyrus re-emerges from the kitchen, with swinging legs and a smile. 

"COME ON, HUMAN. WE CAN FINISH THE JUNIOR JUMBLE.”

Still looking up to the second floor, Frisk points a finger upstairs. The skeleton’s eyes follow the jab, skull tilting as he tries to figure out what the human wants. Frisk still rarely talks and monsters rarely question it.

"OH? YOU WANT TO SEE MY BEDROOM?” Frisk nods in assent with a briskly determined jerk, their whole body swaying with the erratic movement. Papyrus rubs his jawbone in thought, red glove rasping over smooth bone. "HMMMM…” He brightens as his mind latches onto the idea with the speed of a raging wildfire. " **ABSOL-POSITIVELY-LUTEY!** WOWIE! I HAVE HEARD THAT YOU GO INTO A BEDROOM WHEN YOU ARE ON A DATE. THIS IS SO EXCITING! THOUGH I’M NOT SURE WHAT EXACTLY WE’RE MEANT TO DO. PERHAPS MORE PUZZLES?” He sways his hips, bouncing on his heels in excitement.  "LET’S GO RIGHT NOW!”

Papyrus catches Frisk’s hand in a glove as he springs pass them and bounds up the staircase. The child is tugged helplessly after the enthusiastic skeleton. The wood rattles loudly beneath his stomps, and the child scrambles to keep up with the large strides. Breathless laughs escape their lips in the excited flight up to the second floor. It’s so easy to get caught up in Papyrus’s joy; Frisk loves the giddiness of playing with him.

Papyrus pauses to open the heavily decorated wooden door into his bedroom; the smooth round doorknob is difficult to turn with bulky mittens. 

The tall skeleton glances down to see the human staring at Sans’s room again. Pale multicolour light is filtering out from under the door, mesmerising. "THAT’S SANS’S BEDROOM. I NEVER SEE HIM ENTER OR LEAVE, THOUGH.”

Frisk startles at the sudden statement; they had been lost in thought. It was hard to ignore the hope that Sans might remember. She points at the older skeleton’s room with an unspoken question. 

_Can we go visit?_

"SANS DOESN’T LIKE OTHER PEOPLE IN HIS ROOM. AND I RESPECT THAT.” Papyrus harrumphs, placing hands on hips in an exasperated movement. "NO MATTER HOW MESSY IT MIGHT BE IN THERE…” The skeleton fondly grumbles, with a smile. There is a subtle tight worry by his jawbone, which Frisk only sees due to countless timelines of befriending Papyrus. "I ONLY GO IN THERE IF I HAVE TO WAKE HIM UP FOR WORK. HE ALWAYS WASTES THE WHOLE NIGHT NAPPING.” He complains, as he finally pushes the door open.

Frisk watches him gesture inside with a grand sweep of his bone arms.

"MAY I INTRODUCE TO YOU HUMAN THE ROOM OF THE GREAT PAPYRUS, FUTURE ROYAL GUARD AND HERO! NYEHEHEHEH!”

* * *

After half an hour of playing with Papyrus – finishing the newspaper’s Jumble Junior, pretending that the bed was a race car and listening to Pap’s stories about his future exploits – the date inevitably ends with Papyrus declaring that he does not like them romantically. The child accepts this easily enough; Frisk is still unsure of how dates worked, but they always have fun. The rom-dramas they used to watch late at night rarely focused on the actual date – flagrant flirting was common though and Frisk loves trying to imitate the actors. It usually leads to some interesting (if confusing) reactions. 

There is a familiar brief moment of unsure hopefulness as Papyrus asks to be friends, scared that he may have ruined their relationship with his rejection. Frisk smiles like always and asks if they could play again in the future, causing the skeleton to beam at his new friend. 

The scene is always the same, or at least very similar, and it never fails to fill Frisk’s small SOUL with joy. Chara remains bitterly silent, ceasing their narration until Frisk leaves the skeleton brothers’ home. 

Snow comes up to their ankles, teasing the top of their trainers with cold, wet brushes, as they stomp forward towards Waterfall. The crisp sound of snow being packed down is soothing; the rasp of their soles on slush is quiet as the child shuffles through the cold towards warmer climates. Their jumper and shorts are poor protection against the chill in the air; their fingers and nose are already ruby blossoms against their skin.

"heya kiddo.” The voice makes Frisk start, spinning around and sending snow into their socks. The ice is a shock to the warm skin that was safely inside trainers, making them flinch. "had a fun date with my brother?”

The child relaxes as they recognise the skeleton, a twitch of a smile on their lips. Tiny hands clasp at each other, cold pink fingers interlocking as they fidget for warmth. Frisk wasn’t expecting to see Sans again until Waterfall’s sentry station. Caution warred with hope, as she nods.

Sans’s smile widens. "wanna have a chat, kid?”

Frisk pauses before nodding this time. They are hungry and the food at Grillby’s is as delicious as it is greasy. Frisk holds out their hand, waiting for Sans to take it. Sans pauses briefly, looking surprised at the offer. Chara mentally berates them; of course, they shouldn’t act so _expectantly!_ That’s how monsters, Sans in particular, discover the RESETs! Despite this, Sans manages a tight grin, gently takes ahold of the tiny flesh hand and declares that he knows a ‘short cut’. Frisk lets themselves be lead, shivering at the sensation of teleportation. 

Then they keep shivering.

Rather than the cosy, cluttered warmth of Grillby’s, they stand on the edge of a wide stretch of ice – a sparkling frozen pond painted with the reflections of dust-coloured clouds and pokey trees. An icy mirror carved into the snowy landscape. The child glances around in confusion, ducking their head to twist around and stare at the new surrounding. Their hand is still gripped by Sans, neither restricting nor freeing – just holding. The smooth hard bone is warm compared to their chilled fingers. Sans’s hand is large compared to Frisk’s. Every monster’s is; monsters are much bigger creatures than humans. Sans, despite being short for a monster, still towers over Frisk at 5’6.

When Frisk turns back to Sans, they find him observing them calmly with an easy smile. 

"s’up.”

A warning buzzes at the back of their brain, but Frisk rarely heeds warnings. They tilt their head in confusion. Lips part slightly and they breathe out a cloud of gentle condensation.

“Uh… Where?...”

"Ice Lake.” Frisk continues looking puzzled, causing Sans to chuckle slightly. "on reflection, our king is not great at naming things.”

Frisk giggles quietly, holding up their free hand to their mouth. Their breath is warm against the chilled fingers. They glance around this new area again and spot a spark of yellow nearby. Reaching out a tiny hand, they touch it. Their fingertips fall through the insubstantial 4-point star, feeling the cold brush of glitter lick their skin gently. It always reminds Frisk of trailing fingers through fine sand.

_‘Seeing the world reflected in the surface of the ice fills you with Determination.’_

Chara notes quietly, as imperceptible as they were during the first several timelines. Just a toneless voice Frisk had assumed to be their own, or perhaps an imaginary friend’s, inside their head. The unbidden strange knowledge of monsters that was whispered into their ear did not forewarn the naive child that there might be a different person talking to them. Nor did the new advanced reading skills that came with it. They were just a strange child in a stranger place. Was it so foolish to assume that hearing a new voice was normal, perhaps even magical?

Frisk knows better now. 

Chara is waiting. Bidding their time, at least for now.

Frisk turns back to Sans to find him watching them strangely. When their eyes meet, he looks away. 

"how are ya finding Snowdin, kid? it’s a pretty ‘cool’ place, right?” He gestures towards the pond. "ever been ice-skating?”

“Uh…” Frisk can only think of the ice puddles they had drifted over in a slow, unstoppable slide on the way into Snowdin. One of the times had included a puzzle. Did that count?

"wanna?”

Frisk nods slowly, unsure with this strange turn of events. Completely new occasions were rare.

Sans leads them out onto the edge of the ice. Despite being in pink fuzzy slippers, the skeleton is like a rock, solid and sturdy on the slippery surface of the ice. The flimsy slippers do not even slide as the skeleton walks. Frisk grips the edge of his blue jacket, clinging until they are stable enough to gently push away. They stand on the ice, steadier now and with a grin, arms spread out like wings. This was far more difficult than uncontrollably gliding across icy puddles but far more exciting as well.

Sans glances down.

"having fun?”

Frisk nods. Their arms twitch as they fight not to tumble with the small movement. They have fallen down enough in this timeline.

"er, you don’t talk much, do ya kiddo?” At the shake of Frisk’s head, the skeleton continues casually. "that alright. i can appreciate the strong silent type….” Sans pauses, shoving his hands into his pockets. He glances down again, before his eye sockets lock onto Frisk’s vermillion eyes. Their stares meet and are held in place until Sans’s voice gently asks.

"hey, bud… ever heard the name _Chara_ before?”

There is a slow drawn out moment as the words register, as that name registers. The child is suddenly terrified. The friendly tone Sans uses means nothing. If he remembers only Chara, then he will…

Frisk takes an awkward step back and feels the ice disappear beneath her feet. There is a crack and a slap of pain and cold. Their chest freezes as they are suddenly plunged down into an icy void.

**Notes for the Chapter:**

> Don't cry over spilled milk, Pap.
> 
> Frisk is a selective mute - which means they can talk but don't due to severe anxiety.


End file.
